1. Field of the Invention
Embodiments of the invention relate to methods and apparatuses for processing optical subsystems.
2. Background of the Related Art
In the fabrication of fiber optic communication systems, optical interconnects, fiber optics, and other components are assembled to form various interconnected optical subsystems. Typically, optical components are integrated into an optical subsystem that is collectively used to create, for example an optical switch. As the communication industry""s need for optical communication bandwidth has increased, the ability for interconnect surfaces to provide a precise connection between optical subsystems is becoming critical, especially with regard to optical transmission modes that use multiple wavelengths of light to transmit information such as Dense Wavelength Division Multiplexing (DWDM). DWDM is a fiber-optic transmission technique that employs multiple light wavelengths to transmit data parallel-by-bit or serial-by-character. DWDM is a major component of optical networks that allows the transmission of e-mail, video, multimedia, data, and voicexe2x80x94carried in Internet protocol (IP), asynchronous transfer mode (ATM), and synchronous optical network/synchronous digital hierarchy (SONET/SDH), respectively, over fiber optic communication systems.
Generally, fiber optic interconnections include two optical connections mated together to provide a continuous optical path. Conventionally, to form an optical interconnect interface, a fiber optic cable is generally terminated into an optical interconnection called a ferrule that is adapted to connect to optical systems or mating optical interconnects. Ideally, optical interconnects such as ferrules are manufactured with precisely polished and dimensionally optimized interconnect surfaces to provide low insertion loss and to prevent cross talk. Typically, ferrules are polished in batch mode where several ferrules are polished simultaneously with one polishing surface, and often are polished by hand. Unfortunately, as polishing pressure, type of polishing material, and direction of polishing between the surface of the optical components being polished and the polishing surface vary, the conventional batch process often leads to manufacturing issues such as specification repeatability, and undesirable interface aberrations affecting insertion loss, light polarization, extinction ratio, return loss performance, etc. Moreover, as polishing is done in a generally rotating fashion, particles embedded within the polishing material provided can form other aberrations such as scratches, nicks, undercuts, abrasions, etc., that can adversely affect the optical clarity of the interconnect surface and, thus, the optical transmission efficiency.
Typically, interconnection inefficiencies are overcome by additional equipment such as repeaters. Repeaters amplify the optical signal to overcome insertion loss and signal attenuation, thereby extending the optical signal broadcast range. Additionally, testing equipment such as an interferometer is used to precisely test for example, the radius of curvature and apex offset. The radius of curvature is the radius of the interconnect surface and is critical for the proper mating of interconnect surfaces. The apex offset is the measure of the interconnect optical path alignment and is critical for the proper alignment of the optical paths between two optical interconnect surfaces. Unfortunately, testing each interconnection for parameters such as radius of curvature and apex offset increases the manufacturing time and, thus, the cost of the optical subassemblies. Further, for large fiber optic communication systems employing thousands of interconnections, using equipment such as repeaters designed to overcome the interconnect inefficiencies may lead to an overall increase in the cost of the fiber optic communication system. Thus, having optical interface aberrations that affect the transmission of light can adversely affect information flow, reduce the bandwidth, reduce the efficiency of fiber optic communication systems, increase equipment costs, and generally increase the cost of the communication system.
Therefore, there is a need for a method and apparatus to provide a system for polishing optical component interfaces in a simple, repeatable, efficient, and cost effective manner.
Aspects of the invention generally provide a method and apparatus for polishing optical component interfaces used in interconnecting optical subassemblies. In one embodiment, the invention provides an apparatus for processing optical components, including a polishing apparatus having a polishing table and a polishing material supply apparatus adapted to supply polishing material proximate the polishing table, an orbital actuator rotatably coupled to the polishing apparatus and adapted to rotate the polishing apparatus in an orbital motion, and a component support adapted to position an optical component in contact with polishing material adjacent the polishing table.
In another embodiment the invention provides an apparatus for processing optical components, including an orbital actuator rotatably and flexibly coupled to a polishing apparatus having a polishing table, and a polishing material supply apparatus and a polishing material receiver coupled to the polishing apparatus wherein the polishing material supply apparatus is adapted to provide a web of polishing material to the polishing material receiver to define a renewable polishing surface adjacent the polishing table.
In another embodiment the invention provides a method of processing optical components, including rotating a polishing apparatus comprising a polishing table thereon and a polishing material supply apparatus in an orbital direction, providing from the polishing material apparatus a renewable web of polishing material positioned adjacent the polishing table, maintaining a polishing pressure of a surface of an optical component against the web of polishing material and against the polishing table, and polishing the surface.